Sunrise Pest Management | Carpenter ant

Carpenter Ants: Identification, Treatment, and Prevention

Springtime here in the Pacific Northwest is a wonderful thing. Cherry blossoms are in bloom and daffodils are flourishing. But as many of us know, with warm weather comes all kinds of unwanted critters, ants included.

In this article, we’ll be talking about:


Carpenter Ants come in various sizes and colors, so it can sometimes be difficult to identify them when they pop up inside your home. 

The most common species of Carpenter Ant you will encounter in Western Washington is the Camponotus modoc. This species is black with reddish-brown legs, and has various classes which can be identified by their size and anatomy. Queens are typically 16-18mm in length. Workers are smaller, averaging anywhere from 6mm to 13mm in length. 

Due to their varying size, which correlates with their class (Majors being larger and Minors being smaller), Carpenter Ants can be easily misconstrued as another species. During the Spring, you may find Carpenter Ants with wings. These ants are reproductives or swarmers, and are usually a sign of a mature colony. We typically see an increase in activity around March or April as the weather gets warm and these ants appear. 

Throughout these months (and even through the winter), Carpenter Ant reproductives emerge from their nests and swarm. You may even spot activity inside of your home as early as January. It isn’t uncommon to find Carpenter Ants in your home when swarming is taking place. They may have made their way inside by accident, and aren’t cause for immediate concern if you’ve only spotted a few here and there.

Signs of an Infestation

  • Consistent and regular sightings
  • Sawdust or frass in and around your home
  • Rustling sounds in the wall
  • Spotting workers or reproductives
Carpenter Ants are easily identifiable by their traits and habits. It’s important to keep a close eye on activity if you think you may have an infestation. Due to their large numbers and the fact that they utilize the wall voids for travel, it’s important to act fast if you suspect an infestation has begun. These ants can do considerable damage to a structure over time.

Consistent Sightings

If you see a couple of Carpenter Ants one time, you probably don’t have an infestation, and it may just be a scout or wanderer that made its way inside by accident. Make sure you keep an eye on frequency. Regular sightings, such as 2-3 ants per day, is a red flag. If you’re seeing any kind of trailing in your home, contact a licensed pest control expert right away. You may be dealing with an infestation.

Sawdust or Frass

If you have small piles of sawdust in or around your home, you may be dealing with a Carpenter Ant infestation (it isn’t uncommon for this sawdust or “frass” to fall from the ceiling or gather around baseboards). These ants typically start by infesting in water-damaged or decaying wood, but can easily make their way into the sound, dry wood in your crawlspace or walls. 

Unlike other similar pests, Carpenter Ants don’t eat the wood they burrow into. This results in piles of dry frass wherever they have established themselves.

Rustling Noises

Carpenter ant workers burrow into sound wood to create and expand their nests. The galleries they make by doing this will appear finished, almost as if they’ve been sanded. This process can be audible, especially at night when they are most active. The rustling noises they make might sound like leaves or even rodents. When disturbed, the workers will become fairly loud, which can help you pinpoint the activity in your home.

Spotting workers or reproductives

If you see trails of workers or winged reproductives, you likely have a larger problem on your hands. Winged reproductives in particular are a sign of a mature and established colony. By established, we mean that this satellite has been growing and developing anywhere from 4 to 7 years. It is always best to contact a licensed pest control specialist to handle identification and treatment of established activity.

What Not to Do

  • Self-treat with DIYs without consulting a professional
  • Ignore the problem and hope it will go away
  • Try to identify them yourself
  • Fail to take preventative measures

Don’t DIY

It may be tempting to find a more cost-effective way to treat Carpenter Ants yourself. Before you do this, always consult a licensed pest control professional. Often, the over-the-counter or DIY treatments you may find online are not going to be comprehensive or thorough enough to take care of the entire infested colony. 

Substances like peppermint may drive some ants away, but those ants will find another way in unless you turn your home into a full-on candy cane. Other substances such as diatomaceous earth can be messy and ultimately ineffective if the colony is well-established. Many of these solutions may also create a situation wherein other pests are likely to infest, also known as a “conducive condition.” Since some of these materials could be attractants for bees, fleas, moths, or other critters, you’ll want to avoid them. 

Conducive conditions are: wood rot or water damaged wood, heavy vegetation, chicken coups, or bird feeders that are within 50 feet of the structure.

As pest control experts, we have access to both the materials and tools needed to make these substances effective. Over-the-counter solutions are often not specific enough to guarantee the longevity needed to treat these problems. They may not be clinically tested or reliable, and may lead to more time and money spent in the long run. 

Always reach out to a licensed professional before pursuing any DIY treatment method on your own. Should you choose to hire a pest control company, keep in mind that you are not only paying for treatment, but also for the tools, capabilities, and knowledge that professionals have spent decades cultivating. 

Don’t ignore them

Carpenter Ants are unlikely to disappear on their own. Despite common beliefs, they don’t die during the winter. In fact, they spend the colder months advancing their colony, mining out galleries, and taking shelter until Spring rolls around In addition to this, colonies can grow over the course of several years (mature colonies take anywhere from 4 to 7 years to mature). Leaving them alone will only give them the opportunity to establish themselves.

Don’t identify them yourself

Carpenter Ants can generally be easy to identify (to the untrained eye, they’re just a regular big black ant, right?). However, they do vary in color here in Washington. They’re also polymorphic, meaning they have varying sizes depending on class. This can result in mis-identification. 

Smaller Minors might be confused with Thatching Ants, Pavement Ants, or Odorous House Ants. Carpenter ants tend to start their infestation in water damaged, rotting, or wet wood, which could also attract Moisture Ants or Termites. Make sure you know what pest you’re dealing with by contacting a professional first.

Don’t procrastinate prevention

Unfortunately, when it comes to Carpenter Ant infestations in your home, you’re likely only dealing with a Satellite Colony. Primary or Parent Colonies are usually found in the wild in stumps, old growth, or logs. At some point, a few ants made their way into your home and established a Satellite Colony there. 

Even after you have gotten rid of this satellite colony, the invisible pheromone trails that ants use probably still exist, potentially leading to recurring infestations. Currently there is no product out there that can safely and sustainably get rid of these trails. The best way to stop this from happening is to stay two steps ahead of the ants by completing regular preventative services. Because we live in the Pacific Northwest, full eradication just isn’t possible. Often, preventative maintenance is the best solution.

How Sunrise can help

Sunrise Pest uses an Integrated Pest Management method to tackle and control Carpenter Ant infestations. Our technician will complete a thorough inspection for any activity in all areas, including attics and crawl spaces. Not only will he be able to verify the type of ant you’re seeing, but they can also infer other details like the class of the ant, the age of the colony, and the severity of the infestation. 

You don’t need to worry about leaving your home during this service, either. Our licensed and specially trained technicians will administer child and pet-safe materials to the outer perimeter, crawlspace, and wall voids to target active satellite colonies and workers. 

After we complete our treatment, you may continue to see activity for 1 to 2 weeks. After about 14 days, any live ants should appear slow or sluggish. This is a sign that our treatment is making its way through the colony. You shouldn’t see any ant activity after 30 days, but don’t worry if you do. Our service has a 60 day warranty!

Are our products safe?

Absolutely. As an environmentally conscious business, we follow a number of strict federal and state guidelines. We even have an entire Quality Control Department dedicated to ensuring we are performing each service correctly. 

We are more than happy to send the Material Safety and Data Sheets for our services to any customer who requests it. Our top priorities are keeping you informed, safe, and protected.


Here at Sunrise Pest, we know better than anyone that critters are inevitable! We live in their environment as much as they live in ours. That’s why we emphasize taking preventative measures in hopes of reducing the likelihood of infestation. Our comprehensive quarterly treatment plan is our go-to recommendation to our fellow Washingtonians. 

Our All Pest Protection service includes a warranty for any pest that is not currently infested or supported by conducive conditions (similar to a pre-existing condition). This warranty may cover Carpenter Ants, as well. Find out more about how All Pest Protection can protect you and your home here

Related Posts:


Antonelli, Arthur L. Pest Management Study Manual for Pest Control Professionals. Washington State University Extension, 2016. 

“Wood-Infesting Pests-Ant.” Pacific Northwest Pest Management Handbooks, OSU Extension Service – Extension and Experiment Station Communications, 13 Oct. 2016,

About the Authors

This article was created and edited in collaboration with multiple licensed pest control technicians, experts, researchers, and authors.

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